Forming apertures in elastic articles



j F. SLUSHER FORMING APERTURES IN ELASTIC ARTICLES Dec. 5, 195-0 Filed July 24, 1947 Patented Dec. 5, 1950 FORMING APERTURES IN ELASTIC ARTICLES Frank Slasher, Carpinteria, Calif., assignor to The B. F. Goodrich Company, New York, N. Y., a corporation of New York Application July 24, 1947, Serial N0. 763,282

This invention relates to the forming of an aperture in an elastic article in communication with a tubular stem thereon and is especially useful in forming apertures in the inner tubes of pneumatic tires in alignment with valve stems.

In the manufacture of elastic inner tubes of rubber or other rubber-like material for use in pneumatic tires, it has been found convenient to attach a tubular valve stem to the wall of an unvulcanized rubber tube and then to form an aperture through the tube wall in alignment with the passage in the valve stem.

Heretofore, difficulty has been experienced in forming such apertures in that the apertures were not always of sufiicient size and often the material removed to form the aperture remained attached by an edge to the tube and interfered with free passage of air through the valve stem.

It is an object of this invention to overcome the foregoing and other difficulties.

Other objects are to tension or balloon the material of the tube wall in advance of formation of the aperture, to cut the aperture while the material is in stretched condition, and to provide for automatic operation of the cutting mechanism.

These and other objects will appear from the following description and the accompanying drawings.

Of the drawings,

Fig. 1 is a longitudinal sectional elevation of apparatus constructed in accordance with and embodying the invention, parts being broken away.

Fig. 2 is a detail plan view of the cutting mechanism, the blades being open.

Fig. 3 is a similar View with the blade closed.

Fig. 4 is a diagram of the electrical and pneumatic operating mechanism.

Referring to the drawings, the numeral |ll designates an overhanging table portion or horn of a support having an opening therethrough covered by a removable throat plate I I having a central aperture |2 therethrough. A stop I3 is fixed to the top of the table at a distance from the aperture l2 equal to the distance of the valve stem from the near end of the inner tube. The arrangement is such that the open end of the inner tube l may he slipped over the horn with its end at the stop 3 and its valve stem l5 aligned over the aperture l2.

A hand-manipulated socket 20 is adapted to fit over the valve stem and has a connection 2| whereby air under pressure may be supplied to the socket to inflate or balloon the wall of the tube through the aperture |2 by reason of su- 6 Claims. (Cl. 16441) 2 perior pressure in the interior of the valve stem.

Below the plate II, a cutting apparatus is carried by the support for severing the ballooned portion of the tube. The cutting mechanism, as shown, comprises a pair of snips 25 pivotally mounted on a stud 26. The blades of the snips are pivotally connected by links 21, 28 to a sliding cross-head 29 actuated by the piston rod 30 of a double-acting pressure-fluid-operated cylinder 3| secured to the table. The snips, in their open position, as shown in Fig. 2, clear the aperture I2,

For controlling the operation of the snips and thereby severing the ballooned portion from the remainder of the wall of the tube, a bell crank 32 is pivotally mounted on the underside of table II), as at 33 with an arm extending under aperture I2. The other arm supports a permanent magnet 34 adjacent a magnet-operated electrical circuit closer 35. The circuit closer is located in the circuit 36 of a source of current supply 31 and a solenoid 38 of a solenoid valve 39 controlling pressure supply to cylinder 3|. The arrangement is such that as air under pressure is supplied to socket 20 and the socket held over the valve stem, the wall of the tube over aperture I2 is ballooned downwardly. The ballooned material touching the arm of the bell crank swings the magnet 34 toward the circuit closer 35, thereby closing the circuit and energizing valve 39. This forces piston rod 30 to the left, as seen in Figs. 2 and 3, closing the snips to sever the ballooned portion of the tube wall. As the ballooned portion is severed, it releases pressure against the bell crank and the bell crank swings away from the circuit closer, opening the circuit and the snips are opened by return of piston rod 38. The arrangement is such that cutting at a condition of uniform ballooning of the tubes is accomplished automatically.

In operation, the tube is slipped over the horn or table. The operator adjusts the tube against the stop and applies the socket over the valve stem. Air under pressure enters the valve stem ballooning the tube wall, whereupon cutting takes place automatically.

The mechanism is preferably enclosed by a shield 50 and an air jet 5| is supplied for removing the cut material by blowing it out the open end 52 of the shield.

Variations may be made without departing from the scope of the invention as it is defined by the following claims.

I claim:

1. Apparatus for forming an aperture in the wall of an elastic article in communication with a tubular valve stem attached to the wall thereof, said apparatus comprising a support having an aperture therethrough, means for applying pressure to the portion of the wall surrounded by the valve stem to distend the elastic wall of the article through said aperture, and means for removing the distended portion from the article to provide an aperture therein.

2. Apparatus for cutting an aperture in the Wall of an elastic article in communication with a tubular valve stem attached to the wall thereof, said apparatus comprising a support having an aperture therethrough, means for applying pressure to the portion of the wall surrounded by the valve stem to distend the elastic Wall of the article through said aperture, and means for cut ting the distended portion from the article to provide an aperture therein.

3. Apparatus for forming an aperture in the wall of an elastic article in communication with a tubular valve stem attached to the thereof, said apparatus comprising an apertured support for the wall of the article, a socket in alignment with an aperture of the support for receiving said valve stem and applying fluid pressure to said wall to balloon the wall of the article through said aperture of said support, and means for removing :the ballooned portion from the article.

4. Apparatus for cutting an aperture in the wall of an elastic article in communication with a tubular valve stem attached to the wall thereof, said apparatus comprising an apertured support tor the wall of the article, a socket in align.- ment with an aperture of th support for receiving said valve stem and applying fluid pressure to said wall to balloon the Wall of the article through said aperture .of said support, means for cutting the ballooned portion from the article, and means controlled by the ballooned portion of the article for operating said cutting means.

5. Apparatus for cutting an aperture in the wall of an elastic article in communication with a tubular valve stem attached to the wall thereof, said apparatus comprising an apertured support for the Wall or the article, a socket in alignment with an aperture of the .support for receiving said valve stem and applying fluid pressure to ,said wall to balloon the Wall of the article through said aperture of said support, and means for cut- {ting the ballooned portion from the article, said cutting means comprising a pair of shear blades.

6. Apparatus for cutting an aperture in the Wall of an elastic article in communication with a tubular valve stem attached to the wall thereof, said apparatus comprising an apertured support for the wall of the article, a socket in alignment with van aperture of the support for receiving said valve stem and applying fluid pressure to said wall to balloon the wall of the article through said aperture of said support, means for cutting the ballooned portion from the article, and means controlled .by the ballooned portion of the article for operating said cutting means, said cutting means comprisin a pair of shear .blades.

FRANK SLUSl-IER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

